Peter's doctors had long insisted that he go. For a number of years, the Tsar's health had given them concern. It was not his epileptic convulsions that bothered them; they were of short duration, and a few hours after they had passed, Peter seemed quite normal. But fevers—sometimes as a result of unrestricted drinking, sometimes because of the fatigue of travel and worry, sometimes from a mixture of these causes—kept him in bed for weeks. In November 1715, after a drinking bout at Apraxin's house in St. Petersburg, Peter became so ill that the Last Sacrament was given to him. For two days, his ministers and senators remained in an adjacent room, fearing the worst. But within three weeks the Tsar was on his feet and able to go to church, although his face was pale and shrunken. During this illness, one of Peter's physicians went to Germany and Holland for consultation, and returned with the opinion that the patient should travel as soon as possible to Pyrmont near Hanover, where the mineral waters bubbling out of the earth were thought to be milder than the waters of Carlsbad, which Peter had visited previously.
Peter was also going to oversee the marriage of his niece Catherine, the daughter of his half-brother, Ivan. Ivan's wife, Tsaritsa Praskovaya, was devoted to Peter and had allowed her daughters, Anne and Catherine, to be used as marriage partners to promote his German alliances. Anne had married the Duke of Courland in 1709 only to be widowed two months later. Now, Catherine, at twenty-four the older of the two, was to wed the Duke of Mecklenburg, whose small duchy lay on the Baltic coast between Pomerania, Brandenburg and Holstein.
Peter's third purpose in traveling west was to meet his allies, Frederick IV of Denmark, Frederick William of Prussia and George Louis of Hanover, who since September 1714 was now also King George I of England. Peter's ambassador in Copenhagen, Prince Vasily Dolgoruky, had been urging King Frederick IV to join Peter in an allied invasion of the Swedish province of Scania, which lay three miles across the Oresund from the Danish coast of Zealand. Frederick was hesitating, and Peter believed that only by going in person would he be able to persuade the Danes to take what now seemed the only step that could force Charles to end the war.
On January 24, 1716, the royal party left St. Petersburg. With Peter were the senior officials of the Foreign Ministry, Golovkin, Shafirov and Tolstoy, and the rising second-level men, Osterman and Yaguzhinsky. Catherine would look after Peter's health, leaving her little son, Peter Petrovich, three months old, and his sisters, Anne, now eight, and Elizabeth, seven, in the care of the Tsaritsa Praskovaya, who every day wrote a brief but affectionate account of the health and progress of the children. Praskovaya, in turn, was trusting her daughter "Katusha" (Catherine, the intended bride) to Peter's care.
Peter arrived in Danzig on February 18, a Sunday, just in time to attend a church service, accompanied by the Burgomeister. During the sermon, feeling a draft, Peter reached over, removed the Burgomeister's wig and put it on his own head. At the end of the service, he returned the wig with thanks. It was later explained to the startled official that it was Peter's habit, when his head was cold, to borrow a wig from any nearby Russian; in this case, the Burgomeister's had been the handiest.
Although all parties were on hand to celebrate the marriage in Danzig, the terms of the settlement had not yet been worked out. Duke Karl Leopold of Meckleburg has been described as "a tyrannical boor and one of the most notorious little despots that only the decay of the German constitution at that time had allowed to grow up." Meckleburg was small and weak and needed a powerful protector; marriage to a Russian princess would bring the Tsar's support. Knowing that two daughters of Tsar Ivan V were available, not caring which he received, he sent a betrothal ring to St. Petersburg with a letter of proposal in which the name of the recipient had been left blank. Catherine had been chosen.
The wedding took place on April 8, with Peter and King Augustus both present. The bridegroom was dressed in a Swedish-style uniform, with a long Swedish sword, but he forgot to wear his cuffs. At two o'clock, the Tsar's carriage arrived to bring Karl Leopold and his chief minister, Baron Eichholtz, to Peter's house. In front of a crowd of people filling the square before the house, the Duke stepped out of the carriage—and his wig caught on a nail. Bareheaded, he stood in front of the crowd while the faithful Eichholtz scrambled up and detached the wig from the nail. Then, with the bride, who wore the crown of a Russian grand duchess, the party walked through the streets to a small Orthodox chapel which Peter had had built especially for the service. The Orthodox ceremony, performed by a Russian bishop, lasted two hours, during which time Peter moved freely through the congregtion and the choir, prompting in the Psalter and helping with the singing. After the service, as the wedding party again walked through the streets, people in the crowd cried out, "Look! The Duke has no cuffs on!"
In the evening, there was a fireworks display on the square in front of the house where the Duke was staying. Peter led Augustus and the new bridegroom through the crowd, personally setting off the rockets. So long did this last that at one o'clock in the morning Eichholtz had to remind his master that his bride had gone to bed three hours earlier. Karl Leopold departed, but even here Eichholtz had to worry. The bridal chamber had been decorated with many lacquered objects, including a lacquered bed. The Duke hated the sharp odor and Eichholtz feared that he would be unable to sleep on it, but the Duke managed, and the next day the newly married pair and the entire wedding party dined with a satisfied and happy Peter. The festivities ended badly, however, when officials in both parties fell to squabbling over the exchange of commemorative gifts. The Duke had made handsome presents to the Russian ministers, but the Mecklenburgers received nothing—"not even a crooked pin." Worse, Tolstoy, who was used to the exchange of fabulous stones in Constantinople, complained that the ring he received was less valuable than those presented to Golovkin and Shafirov. Osterman, a junior diplomat in the Russian party, tried to calm Tolstoy's wrath by giving him also the small ring with which he had been presented, but Tolstoy continued to complain that he had been insulted.
To Peter's chagrin, the marriage caused grave complications with his North German allies, especially Hanover, which, with Prussia, had joined Russia, Denmark and Poland against Sweden. The common motive of these new allies was to expel Charles XII from the continent and to pick up and distribute among themselves the pieces of former Swedish territory inside the Holy Roman Empire. Increasingly, however, they began to realize that the destruction and disappearance of Swedish power was being accompanied by the rise of a new and greater power, that of the Russian Tsar. Until the Meckleburg marriage, the suspicions of the North German princes remained beneath the surface. In July 1715, the Danish and Prussian troops besieging Stralsund had even asked for Russian help. Sheremetev's army lay in western Poland and could easily have marched, but Prince Gregory Dolgoruky, the experienced Russian ambassador in Warsaw, feared that the situation in Poland was still too volatile and insisted that Sheremetev stay where he was. Accordingly, Stralsund fell without the participation of a single Russian soldier. When he heard the news, Peter was furious at Dolgoruky: "I am truly astonished that you have gone out of your mind in your old age and have let yourself be carried away by these constant tricksters and so have held these troops in Poland."